Hydrokinetic coupling apparatus in particular for motor vehicle

Abstract

The invention concerns an apparatus comprising a housing ( 12 ) with a radial wall ( 14 ) coupled with another input shaft, a turbine wheel ( 104 ) coupled with a hub ( 54 ) and an output shaft; and a lockup clutch comprising a piston ( 40 ); an annular friction disc ( 152 ) with global radial orientation, coupled in rotation with the turbine wheel ( 104 )/hub ( 54 ) assembly and bearing on a first surface a first counter-track ( 210 ) co-operating with a first friction track ( 200 ) integral with the piston to define a first annular friction zone (Z 1 ), and which bears on its second surface opposite to the first surface, a second counter-track ( 230 ) co-operating with a second friction track ( 220 ) integral with the radial wall ( 14 ) to define a second annular friction zone (Z 2 ). The invention is characterized in that the first and second friction zones (Z 1, Z 2 ) are radially offset relative to each other.

What is claimed is:  
     
       1. A fluid coupling apparatus ( 10 ), especially for a motor vehicle, of the type comprising: 
       a casing ( 12 ) having a generally radially oriented wall ( 14 ) adapted to be coupled in rotation to a driving shaft;  
       a turbine wheel ( 104 ) coupled in rotation to a hub ( 54 ) which is adapted to be coupled in rotation to a driven shaft;  
       a lock-up clutch, operatively interposed between the turbine wheel ( 104 ) and the radial wall ( 14 ), and comprising, disposed axially between the turbine wheel and the radial wall, and going from front to rear in this order:  
       a generally radially oriented piston ( 40 ) which is movable axially and coupled in rotation to the casing;  
       a generally radially orientated annular friction disc ( 152 ), coupied in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ), and carrying on a first face a first counteracting face ( 210 ) which is in cooperation with a first friction face ( 200 ) fixed to the piston for defining a first annular friction zone (Z 1 ), the friction disc carrying on its second face, opposed to the first face, a second counteracting face ( 230 ) which is in cooperation with a second friction face ( 220 ) fixed to the radial wall ( 14 ) for defining a second annular friction zone (Z 2 ),  
       characterised in that the first and second friction zones (Z 1 , Z 2 ) are offset radially from each other.  
     
     
       2. Apparatus according to  claim 1 , characterised in that each friction zone (Z 1 , Z 2 ) is delimited radially, firstly by an outer diameter (D 1 ext, D 2 ext), and secondly, by an inner diameter (D 1 int, D 2 int), and in that the outer diameter (D 1 ext, D 2 ext) of one of the two friction zones (Z 1 , Z 2 ) is greater than the outer diameter (D 2 ext, D 1 ext) of the other one of the two friction zones (Z 2 , Z 1 ), and in that the inner diameter (D 2 int, D 1 nt) of the said other friction zone (Z 2 , Z 1 ) is smaller than the inner diameter (D 1 int, D 2 int) of the said one friction zone (Z 1 , Z 2 ). 
     
     
       3. Apparatus according to  claim 2 , characterised in that the outer diameter (D 1 ext, D 2 ext) of the said one friction zone (Z 1 , Z 2 ) is smaller than the inner diameter (D 2 int, D 1 int) of the said other friction zone (Z 2 , Z 1 ). 
     
     
       4. Apparatus according to  claim 1 , characterised in that the friction disc ( 152 ) is coupled in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ) through interposed damping means comprising two coupling members ( 114 ,  128 ), one of which is coupled in rotation to the friction disc ( 152 ) while the other is coupled in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ), the said coupling members being in cooperation with each other through interposed circumferentially acting resilient members ( 122 ). 
     
     
       5. Apparatus according to  claim 4 , characterised in that a first coupling member ( 114 ) is fixed with respect to the assembly of the turbine wheel ( 104 ) and hub ( 54 ), and the second coupling member ( 128 ) is fixed to the friction disc ( 152 ). 
     
     
       6. Apparatus according to  claim 5 , characterised in that the second coupling member ( 128 ) is disposed generally in facing relationship with the second counteracting face ( 230 ). 
     
     
       7. Apparatus according to  claim 5 , characterised in that the second coupling member ( 128 ) is integral with the friction disc ( 152 ). 
     
     
       8. Apparatus according to  claim 4 , characterised in that a first coupling member ( 114 ) is fixed to the friction disc ( 152 ), and the second coupling member ( 128 ) is fixed to the assembly of the turbine wheel ( 104 ) and hub ( 54 ). 
     
     
       9. Apparatus according to  claim 8 , characterised in that the first coupling member ( 114 ) is integral with the friction disc ( 152 ). 
     
     
       10. Apparatus according to  claim 8 , characterised in that the first coupling member ( 114 ) comprises a member for guiding the circumferentially acting resilient members ( 122 ), and has zones ( 124 ,  126 ) for engagement with the said resilient members ( 122 ). 
     
     
       11. Apparatus according to  claim 10 , characterised in that the member for guiding the resilient members ( 122 ) comprises a substantially annular portion ( 114 ) configured with an axial groove in which the circumferentially acting resilient members ( 122 ) are lodged. 
     
     
       12. Apparatus according to  claim 11 , characterised in that the axial groove is open towards the radial wall ( 14 ). 
     
     
       13. Apparatus according to  claim 11 , characterised in that the axial groove is open away from the radial wall ( 14 ). 
     
     
       14. Apparatus according to  claim 5 , characterised in that the second coupling member ( 128 ) includes elements for abutment of the circumferentially acting resilient members ( 122 ). 
     
     
       15. Apparatus according to  claim 11 , characterised in that abutment elements of the second coupling member ( 128 ) penetrate into the axial groove of the substantially annular portion ( 114 ), whereby each of them is received between the two circumferential ends of two consecutive circumferentially acting resilient members ( 122 ). 
     
     
       16. Apparatus according to  claim 5 , characterised in that abutment elements of the second coupling member ( 128 ) are integral with a member ( 94 ;  152 ) fixed to the assembly of the turbine wheel ( 104 ) and hub ( 54 ) or to the friction disc ( 152 ). 
     
     
       17. Apparatus according to  claim 16 , further comprising elements ( 262 ) for entrapment of the resilient members ( 122 ), formed integrally with the member ( 94 ;  152 ), the abutment elements of the second coupling member ( 128 ) being formed integrally with the member ( 94 ;  152 ) and interposed between the entrapment elements ( 262 ) for the resilient members ( 122 ). 
     
     
       18. Apparatus according to claims  1 , characterised in that the friction disc ( 152 ) is coupled in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ) through interposed rigid means ( 276 ,  278 ). 
     
     
       19. Apparatus according to  claim 18 , characterised in that the first and second counteracting faces ( 210 ,  230 ) are each part of at least one friction liner ( 245 ,  245 ′) attached directly or indirectly, either on the friction disc ( 152 ) or on the piston ( 40 ) and the radial wall ( 14 ), or on at least one of the faces of the friction disc ( 152 ) and on the piston ( 40 ) or the radial wall ( 14 ) of the casing ( 12 ). 
     
     
       20. Apparatus according to  claim 7 , characterised in that abutment elements of the second coupling member ( 128 ) are joined to the outer periphery of the friction disc ( 152 ) carrying the first counteracting face ( 210 ), and in that the second counteracting face ( 230 ) is part of at least one supplementary member ( 242 ) fixed on at least one of the abutment elements ( 128 ) or on the friction disc ( 152 ). 
     
     
       21. Apparatus according to  claim 7 , characterised in that abutment elements of the second coupling member ( 128 ) are formed by pressing and bending to project from the friction disc ( 152 ). 
     
     
       22. Apparatus according to  claim 7 , characterised in that abutment elements of the second coupling member ( 128 ) are joined to the friction disc ( 152 ) through a bend ( 246 ), and in that the second counteracting face ( 230 ) is fixed to a first shim ( 251 ) which covers at least a major part of openings ( 253 ) defined by the friction disc ( 152 ) radially outwards of the abutment elements ( 128 ) whereby to define the latter, and in that the shim ( 251 ) extends transversely, radially inwards of the bend ( 246 ), to provide sealing between the radial wall ( 14 ) and the friction disc ( 152 ) when the latter is gripped between the first and second faces ( 200 ,  220 ). 
     
     
       23. Apparatus according to  claim 22 , characterised in that the first shim ( 251 ) is fixed in contact with the friction disc ( 152 ). 
     
     
       24. Apparatus according to  claim 23 , characterised in that the first counteracting face ( 210 ) is fixed with respect to a second shim ( 252 ) fixed on the friction disc ( 152 ). 
     
     
       25. Apparatus according to  claim 24 , characterised in that each shim ( 251 ,  252 ) has a support zone for its associated friction liner ( 245 ,  245 ′), and in that the support zones are offset axially away from the friction disc ( 152 ) with respect to the fastening zones ( 260 ) in contact with the friction disc ( 152 ). 
     
     
       26. Apparatus according to  claim 9 , characterised in that the friction disc ( 152 ) is configured in two parts, namely an outer part and an inner part respectively, the outer part of the said friction disc ( 152 ) constituting an annular portion ( 114 ) of a guide member, and the inner part of the said friction disc ( 152 ) defining a collar ( 266 ) which extends the annular portion ( 114 ) radially. 
     
     
       27. Apparatus according to  claim 26 , characterised in that the first and second counteracting faces ( 210 ,  230 ) are attached on a base ( 118 ) which delimits the axial groove, and on the collar ( 266 ) which extends the annular portion ( 114 ) radially. 
     
     
       28. Apparatus according to  claim 13 , characterised in that the annular portion ( 114 ) of the guide member is coupled in rotation to the assembly of the turbine wheel ( 114 ) and hub ( 54 ) by meshing of teeth ( 268 ) with complementary notches ( 270 ) formed on the annular portion ( 114 ) and the assembly of the turbine wheel ( 104 ) and hub ( 54 ), the said teeth extending substantially at right angles to the complementary notches. 
     
     
       29. Apparatus according to  claim 28 , characterised in that the friction disc ( 152 ) is formed with an inner axial stiffening flange ( 500 ). 
     
     
       30. Apparatus according to  claim 18 , characterised in that the friction disc ( 152 ) is coupled in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ) by meshing of teeth ( 276 ) with complementary notches ( 278 ) formed on the friction disc ( 152 ) and the assembly of the turbine wheel ( 104 ) and hub ( 54 ). 
     
     
       31. Apparatus according to  claim 30 , characterised in that the teeth ( 276 ) and complementary notches ( 278 ) are carried by a peripheral axial flange ( 286 ) of the friction disc ( 152 ), and by a peripheral radial portion ( 288 ) of a component ( 94 ) of the assembly of the turbine wheel ( 104 ) and hub ( 54 ). 
     
     
       32. Apparatus according to  claim 30 , characterised in that the teeth ( 276 ) and complementary notches ( 278 ) are carried by a peripheral axial flange ( 280 ) of a component ( 94 ) of the assembly of the turbine wheel ( 104 ) and hub ( 54 ), and by a peripheral radial portion ( 282 ) of the friction disc ( 152 ). 
     
     
       33. A fluid coupling apparatus ( 10 ) comprising: 
       a casing ( 12 ) having a generally radially oriented wall ( 14 ) adapted to be coupled in rotation to a driving shaft;  
       a turbine wheel ( 104 ) coupled in rotation to a hub ( 54 ) which is adapted to be coupled in rotation to a driven shaft;  
       a lock-up clutch, operatively interposed between the turbine wheel ( 104 ) and the radial wall ( 14 ), and comprising, disposed axially between the turbine wheel and the radial wall, and going from front to rear in this order:  
       a generally radially oriented piston ( 40 ) which is movable axially and coupled in rotation to the casing;  
       a generally radially orientated annular friction disc ( 152 ), coupled in rotation to the assembly of the turbine wheel ( 104 ) and hub ( 54 ), and carrying on a first face a first counteracting face ( 210 ) which is in cooperation with a first friction face ( 200 ) fixed to the piston for defining a first annular friction zone (Z 1 ), the friction disc carrying on its second face, opposed to the first face, a second counteracting face ( 230 ) which is in cooperation with a second friction face ( 220 ) fixed to the radial wall ( 14 ) for defining a second annular friction zone (Z 2 ),  
       wherein said first and second friction zones (Z 1 , Z 2 ) are radially offset,  
       said first and second friction zones comprising axially substantially non-overlapping areas.